HOWTO make glowing inkjet ink
I am surprised that I have not seen more specialty/ small batch ink manufacturers selling filled syringes for inkjet cartridges. It may be that ink- unless it glows in the dark or under UV light- has trouble differentiating itself and still spraying correctly through the printer nozzle.
This Metacafe video shows a simple method of making your own glow-in-the-dark inkjet printer ink, in any color you choose. Pretty sassy. My most-favorite-ever Haunted Mansion souvenir was this postcard showing a straightlaced man that had been painted with transparent glow-ink; when you turned the lights off, the glow-ink turned the picture into that of a ferocious werewolf. Alas, I lost that card the same night I got it (rental car broke down on the way home and I was sleeping in the back, I forgot it there and it never resurfaced) and I have been searching for a replacement since 1977. I'm wondering if I could do spot-color with this and make my own. Link
HOWTO make glowing inkjet ink
via Boing Boing by Cory Doctorow on Jun 18, 2007
Cory Doctorow: This Metacafe video shows a simple method of making your own glow-in-the-dark inkjet printer ink, in any color you choose. Pretty sassy. My most-favorite-ever Haunted Mansion souvenir was this postcard showing a straightlaced man that had been painted with transparent glow-ink; when you turned the lights off, the glow-ink turned the picture into that of a ferocious werewolf. Alas, I lost that card the same night I got it (rental car broke down on the way home and I was sleeping in the back, I forgot it there and it never resurfaced) and I have been searching for a replacement since 1977. I'm wondering if I could do spot-color with this and make my own. Link 
